Friday, 19 September 2008
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POST 01325E: FUTURE COLD CHAIN TRENDS 19 SEPTEMBER 2008 ******************************************* On 10 and 11 June 2008, a meeting was held on Cool Chain Technologies for the Future (organized by PATH) at Mijoux, France. Prior to the meeting, discussions were held with cold chain equipment manufacturers. The major strategic issues were identified as increased vaccine volumes, the introduction of new vaccines and reduced need for freezing. The need for cold chain expansion was projected in view of new, more bulky and predominantly single dose vaccines. The moderating effect of switching to thermo-stable vaccines was acknowledged but was presented as having a long time horizon (>10 years), affecting some, not all, vaccines and releasing some vaccines from the cold chain only at the periphery at first. Scenarios were presented to determine the product requirements that may materialize with these changes. Four main issues emerged from the meetings relating to primary storage and distribution: 1. Vaccine chilled rooms will be much larger, more numerous The volume of vaccines needing to be refrigerated at the primary store level will increase almost eight-fold and will require larger cold rooms or more cold rooms. The existing cold room equipment in the national stores and, typically, in the province/regional stores will need to be expanded, and cold rooms will be preferred instead of refrigerators at a larger number of lower-level intermediate stores. 2. Freeze-safe Ice Lined Refrigerators (ILRs) more widely used New models of the ice-lined refrigerator will be introduced to meet the PQS by March 2009. These models will not freeze vaccine in any storage area and will be fitted with fixed thermostats that cannot be adjusted by the user. The current ILR models will be used in smaller stores in the more voluminous vaccine scenarios. New models were discussed with manufacturers based on larger gross capacities (400 litres). These larger capacities will enable ILRs to be used in stores which otherwise would have required a cold room. 3. Potential use of chilled transport containers for vaccine distribution Vaccines are now distributed typically in cold boxes of around 20-25 litres capacity with about 15 litres of icepacks. The external volume of a long-range cold box is about six times the volume of the vaccine. It is probably more practical and more economic (in terms of use of transport) to pack vaccines either in an actively refrigerated vehicle or ‘reefer’, or large volume (1.2m3) containers may be used. These containers are already manufactured and used in distribution of chilled food in supermarket chains in Europe with either active refrigeration ‘on board’ or using passive cooling by eutectic-filled panels that are pre-frozen and inserted with the produce. The containers on rolling wheels may either be loaded onto trucks, several at a time, using tail elevators or they may be bolted into the back of pick-up and double-cab vehicles. 4. Chilled water pack cooling required Until recently, icepacks were frozen and used as a coolant for cold boxes in the distribution of vaccines. The policy now recommends switching to chilled water packs instead of frozen icepacks to avoid the accidental freezing of vaccine. Water packs at ambient temperature cannot be placed with vaccines to cool in the same refrigerator; so separate dedicated refrigerators will be needed. One manufacturer with existing icepack fast freezer models and several manufacturers with chest freezer models confirmed that they could offer modified models to chill water packs quickly. Impact on Health Centre and Outreach Ø Small-sized refrigerators (very low workload) or Out of Cold Chain and no refrigerators Ø More larger refrigerators 20-70 litres Ø Larger vaccine carriers Ø More water/ice packs Impact on Health Centre storage of energy costs Ø High efficiency compression type ILRs Ø Low efficiency absorption type refrigerators/IPFs Ø Importance of making solar PV work Impact on facility storage and outreach Ø Flexibility for more new vaccines in small HCs Ø Larger refrigerators at average HC facilities Fuel cost & efficiency suggests: Ø Maximum use of compression as against absorption models Ø Widespread introduction of solar PV Ø Multiple vaccine carriers will be needed for outreach Post generated using Mail2Forum (http://www.mail2forum.com)
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